{
  "_meta": {
    "__meta__": "synthetic",
    "disclaimer": "Synthetic demo data inspired by real Baltic geography, MMSI/OUI conventions, and infrastructure. Not real observations.",
    "dataset": "s2-rendezvous/timeline",
    "version": "1.0",
    "anchor_ts": "2025-04-12T11:00:00Z",
    "window_open_ts": "2025-04-12T08:00:00Z",
    "window_close_ts": "2025-04-13T01:30:00Z",
    "rendezvous_point": {"lat": 59.4200, "lon": 23.0500, "note": "~38 NM south of Hanko"}
  },
  "events": [
    {"ts_iso": "2025-04-12T08:00:00Z", "t_rel": "T-03:00:00", "event": "MV SAIMAA AURORA (230999081) on WB transit off Kotka approach; MV NEVA CASCADE (273999142) EB from Tallinn approach", "signals": ["ais"], "notes": "Baseline AIS cadence 10 s underway."},
    {"ts_iso": "2025-04-12T08:45:00Z", "t_rel": "T-02:15:00", "event": "AURORA makes 12° starboard course change, off declared route toward A3 (59.82, 24.60)", "signals": ["ais"], "notes": "Within weather-avoidance plausibility."},
    {"ts_iso": "2025-04-12T09:10:00Z", "t_rel": "T-01:50:00", "event": "CASCADE drops SOG 13.2 kn → 9.5 kn", "signals": ["ais"], "notes": "First speed-anomaly knob; below historical P1 for this MMSI."},
    {"ts_iso": "2025-04-12T09:40:00Z", "t_rel": "T-01:20:00", "event": "Patrol drone RAD-DRN-PAT-01 launches from Hanko Coast Guard Station (59.8240, 22.9650), MAC-AIR-DRN-01 warms up", "signals": ["drone_radar", "mac"], "notes": "Drone telemetry begins."},
    {"ts_iso": "2025-04-12T10:15:00Z", "t_rel": "T-00:45:00", "event": "Drone enters 1.5 km orbit at 1200 m AGL over predicted RV point (59.4205, 23.0510)", "signals": ["drone_radar", "mac"], "notes": "Orbit period ~336 s; airspeed ~28 m/s."},
    {"ts_iso": "2025-04-12T10:30:00Z", "t_rel": "T-00:30:00", "event": "AURORA and CASCADE within 2 NM of each other; both below 8 kn", "signals": ["ais", "drone_radar"], "notes": "Proximity-detection trigger #1."},
    {"ts_iso": "2025-04-12T10:45:00Z", "t_rel": "T-00:15:00", "event": "Ships within 500 m; speeds 2.1 / 1.8 kn; first airborne MAC hits on AURORA and CASCADE crew sets", "signals": ["ais", "drone_radar", "mac"], "notes": "P-SAU-MASTER (a4:83:e7:5c:9b:21) and P-NEV-MASTER (00:e0:fc:77:88:31) seen by MAC-AIR-DRN-01."},
    {"ts_iso": "2025-04-12T11:00:00Z", "t_rel": "T+00:00:00", "event": "Near-stop window BEGINS — distance 55–80 m, SOG 0.4–0.8 kn; burst of 22 locally-administered 02:* MACs appears on MAC-AIR-DRN-01", "signals": ["ais", "drone_radar", "mac"], "notes": "deviceManufacturer = null on all burst MACs."},
    {"ts_iso": "2025-04-12T11:08:00Z", "t_rel": "T+00:08:00", "event": "Drone descends to 700 m for closer MAC capture; RSSI for ship-attributed MACs jumps +10 to +14 dB", "signals": ["drone_radar", "mac"], "notes": "Drives co_observation_score to 1."},
    {"ts_iso": "2025-04-12T11:20:00Z", "t_rel": "T+00:20:00", "event": "Burst MAC count peaks (≈ 22 unique 02:* MACs across both hulls); mac_count_zscore spikes", "signals": ["mac"], "notes": "Airborne per-minute count well above 90-day baseline μ+3σ."},
    {"ts_iso": "2025-04-12T11:30:00Z", "t_rel": "T+00:30:00", "event": "Peripheral plane RAD-PLN-01 (Dornier 228-class) closest pass ~22 NM south at 3000 m", "signals": ["plane_radar", "mac"], "notes": "MAC-AIR-PLN-01 picks up only 1–2 long-range crew MAC hits (path-loss limited)."},
    {"ts_iso": "2025-04-12T11:35:00Z", "t_rel": "T+00:35:00", "event": "Ships begin to separate; SOG climbs to 3 kn; burst MAC count decays", "signals": ["ais", "drone_radar", "mac"], "notes": "RV near-stop window ENDS."},
    {"ts_iso": "2025-04-12T11:50:00Z", "t_rel": "T+00:50:00", "event": "Distance > 1 NM; AIS courses diverge (AURORA → NW toward Hanko, CASCADE → SE then NE toward Helsinki)", "signals": ["ais"], "notes": "Classic 'meet and part'."},
    {"ts_iso": "2025-04-12T12:10:00Z", "t_rel": "T+01:10:00", "event": "Drone breaks orbit, RTB Hanko Coast Guard Station; last airborne MAC frames", "signals": ["drone_radar", "mac"], "notes": "Drone climb back to 1200 m, descent to base."},
    {"ts_iso": "2025-04-12T13:30:00Z", "t_rel": "T+02:30:00", "event": "Both vessels back on plausible commercial headings", "signals": ["ais"], "notes": "RAD-PLN-01 peripheral confirmation logged in transit."},
    {"ts_iso": "2025-04-12T20:15:00Z", "t_rel": "T+09:15:00", "event": "AURORA berths Hanko port quay 4; MAC-HKO-PORT-01/02/03 pick up 6 of the 22 burst MACs over ~90 min", "signals": ["mac", "ais"], "notes": "Cross-port re-appearance #1 — physical-layer evidence of inter-hull transfer."},
    {"ts_iso": "2025-04-13T00:40:00Z", "t_rel": "T+13:40:00", "event": "CASCADE berths Helsinki West Harbour; MAC-HEL-PORT-01/02 pick up 5 of the 22 burst MACs over ~90 min", "signals": ["mac", "ais"], "notes": "Cross-port re-appearance #2; 2 burst MACs overlap with the Hanko set within ±90 min."},
    {"ts_iso": "2025-04-13T01:30:00Z", "t_rel": "T+14:30:00", "event": "Dense capture window closes; analyst pipeline runs fused proximity + MAC co-occurrence join", "signals": ["compute"], "notes": "Final S2-RV-2025-04-12 incident_score raised per weights.json."}
  ]
}